A brake system for a motor vehicle, and in particular an automotive vehicle, functionally reduces the speed of the vehicle or maintains the vehicle in a rest position. Various types of brake systems are commonly used in automotive vehicles, including hydraulic, anti-lock, also referred to as ABS, and electric, also referred to as "brake by wire." For example, in a hydraulic brake system, the hydraulic fluid transfers energy from a brake pedal to a brake pad for slowing down or stopping rotation of a wheel of the vehicle. Electronics control the hydraulic fluid in the hydraulic brake system. In the electric brake system, the hydraulic fluid is eliminated. Instead, the application and release of the brake pad is controlled by an electric caliper.
Traditionally, hydraulic fluid is a very efficient means of transferring a load, since a brake system in an automotive vehicle must be able to transfer a load of about fourteen thousand (14,000) pounds. An electric brake system accomplishes this load transfer through the electric caliper. Generally, the electric caliper includes a motor and a gear system. Typically, either a few large gears or many small gears for the gear system are needed to achieve the comparable load transfer as the hydraulic fluid. Also, the geometry of the motor influences its efficiency, since the preferred shape is long and thin. However, there is a limited amount of space available in the wheel for packaging the type of gears or motor necessary to obtain the same load transfer as in the hydraulic brake system. Therefore, space limitations constrain the use of an electric caliper in an automotive vehicle. Thus, there is a need in the art to provide an electric caliper for a brake system that is efficient and can be packaged within the available space of a wheel.